Keywords : Crystal structures, Vanadate complexes, Oxoperoxo complexes, Lactate complexes, Isomers

Introduced complexes (Bu₄N)₂[VO(O₂)(C₃H₄O₃)]₂.2H₂O are first of structures existing with LL and DL configurations.

Crystals of compounds (1) and (2) were prepared by dissolving V₂O₅ in a solution Bu₄NOH. Green solutions were cooled at room temperature and water, efficient lactate acid and H₂O₂ were slowly added. Red crystalline complexes were formed on free crystallization at low temperature (4°C) by one day.

Both the crystal structures consist of a dimeric anion [VO(O₂)(C₃H₄O₃)]₂^2-, two Bu₄N⁺ cations and two water molecules, which packed in the crystal by hydrogen bonds and van der Waals interactions.

The lactato ion of both complexes coordinating to vanadium forms a pentaatomic chelation ring. Two of these rings are joined together by the hydroxyl O atoms from the lactato acid. These hydroxyl O atoms bridging two adjacent vanadium atoms form a central four-membered V₂O₂ planar heterocycle. Coordination about vanadium atoms is completed to a distorted pentagonal pyramid with oxo O1 atom as an apex. The maximum deviation from the plane through the atoms V1, V1a, O4, O4a, O5, O6, C1 and C2 is less than 0.1Å.

Introduced compounds are at issue only in the geometric orientation of their peroxo groups. Both peroxo groups linking to vanadium atoms in the compound (1) are oriented at the same part of a plane, the orientation of peroxo groups is opposite in the compound (2).

The basic crystallographic data for monoclinic single crystals of compounds (1) and (2) are :

(1) : empirical formula - C₁₉H₄₀NO₇V (2) : empirical formula - C₁₉H₄₀NO₇V

space group - P2(1)/n space group - P2(1)

cell dimension - a=12.669(5) Å cell dimension - a=12.771(2) Å

b=14.64 (2) Å b=14.391(2) Å

c=12.740(5) Å c=13.333(2) Å

â=101.76(4)° â=101.45(1)°

volume - 2314(3) ų volume - 2401.6(6) ų

Z = 4 Z = 4

R₁/wR₂ [I>2ó(I)] - 0.0623/0.1598 R₁/wR₂ [I>2ó(I)] - 0.0596/0.1402

R₁/wR₂ [all data] - 0.1127/0.1892 R₁/wR₂ [all data] - 0.1763/0.1848

ORTEP view of a dimeric anion [VO(O₂)(C₃H₄O₃)]₂^2- in compounds (1) and (2)